Viral inhibitors

ABSTRACT

Pyrrolo[2,3-c]pyridine or pyrrolo[3,2-c]pyridine compounds having the general formula (A), 
                         
wherein the dashed lines, X, Y and R 1  through R 5  are as defined in the specification. The compounds are useful in the prophylaxis or treatment of viral infections.

This non-provisional application is a divisional of U.S. applicationSer. No. 11/957,017, filed Dec. 14, 2007, which claims the benefit ofProvisional Application No. 60/874,797, filed Dec. 14, 2006, both ofwhich are incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a series of novelpyrrolo[2,3-c]pyridines and pyrrolo[3,2-c]pyridines, processes for theirpreparation, their use to treat or prevent viral infections and theiruse to manufacture a medicine to treat or prevent viral infections,particularly infections with viruses belonging to the family of theFlaviviridae and more preferably infections with hepatitis-C-virus(HCV).

BACKGROUND OF THE INVENTION

The World Health Organization estimates that world-wide 170 millionpeople (3% of the world's population) are chronically infected with HCV.These chronic carriers are at risk of developing cirrhosis and/or livercancer. In studies with a 10 to 20 year follow-up, cirrhosis developedin 20-30% of the patients, 1 to 5% of whom may develop liver cancerduring the next then years. The only treatment option available today isthe use of interferon α-2 (or its pegylated form) either alone orcombined with ribavirin. However, sustained response is only observed inabout 40% of the patients and treatment is associated with seriousadverse effects. There is thus an urgent need for potent and selectiveinhibitors of the replication of the HCV in order to treat infectionswith HCV. Furthermore, the study of specific inhibitors of HCVreplication has been hampered by the fact that it is not possible topropagate HCV (efficiently) in cell culture. Since HCV and pestivirusesbelong to the same virus family and share many similarities(organization of the genome, analogous gene products and replicationcycle), pestiviruses have been adopted as a model and surrogate for HCV.For example BVDV is closely related to hepatitis C virus (HCV) and usedas a surrogate virus in drug development for HCV infection.

In view of their important pharmacological value, there is a need fordrugs having antiviral activity, optionally selective activity againstviruses belonging to the family of Flaviviridae including hepatitis Cvirus, and against viruses belonging to the family of Picornaviridae.

SUMMARY OF THE INVENTION

The invention relates to the use of pyrrolo[2,3-c]pyridines andpyrrolo[3,2-c]pyridines, as antiviral compounds, more particularly ascompounds active against HCV, which correspond to the general formula(A),

wherein:

the dotted lines represent at least 3, optionally 4 double bonds,provided that no two double bonds are adjacent to one another;

A is —N═ or CR²⁶, but one A is CR²⁶;

R¹ is selected from hydrogen, aryl, heterocycle, C₁-C₁₀ alkoxy, C₁-C₁₀thioalkyl, C₁-C₁₀ alkyl-amino, C₁-C₁₀ dialkyl-amino, C₃₋₁₀ cycloalkyl,C₄₋₁₀ cycloalkenyl, and C₄₋₁₀ cycloalkynyl, wherein each are optionallysubstituted with 1 to 3 R⁶;

Y is selected from a single bond, O, S(O)_(m), NR¹¹, C₁₋₁₀ alkylene,C₂₋₁₀ alkenylene, or C₂₋₁₀ alkynylene, wherein 1 to 3-C(H)═, —C(≡) or—CH₂— groups of each alkylene, alkenylene or alkynylene optionally areindependently replaced with a heteroatom or heteroatom group selectedfrom —O—, ═O, —OR²⁷, —S—, ═S, —SR²⁷, —NR²⁷, —N(R²⁷)₂ where R²⁷independently is hydrogen, C₁₋₁₈ alkyl, C₂₋₁₈ alkenyl, or C₂₋₁₈ alkynyl;

provided that YR¹ is not hydrogen or C₁₋₆ alkyl;

R² and R⁴ are independently selected from hydrogen, C₁₋₁₈ alkyl, C₂₋₁₈alkenyl, C₂₋₁₈ alkynyl, C₁₋₁₈ alkoxy, C₁₋₁₈ alkylthio, halogen, —OH,—CN, —NO₂, —NR⁷R⁸, haloalkyloxy, haloalkyl, —C(═O)R⁹, —C(═S)R⁹, SH,aryl, aryloxy, arylthio, arylalkyl, C₁₋₁₈ hydroxyalkyl, C₃₋₁₀cycloalkyl, C₃₋₁₀ cycloalkyloxy, C₃₋₁₀ cycloalkylthio, C₃₋₁₀cycloalkenyl, C₃₋₁₀ cycloalkynyl, or heterocycle;

X is absent or is selected from hydrogen, C₁-C₁₀ alkylene, C₂₋₁₀alkenylene or C₂₋₁₀ alkynylene, wherein 1 to 3-C(H)═, —C(≡) or —CH₂—groups of each alkylene, alkenylene or alkynylene optionally areindependently replaced with a heteroatom or heteroatom group selectedfrom —O—, ═O, —OR²⁷, —S—, ═S, —SR²⁷, —NR²⁷, —N(R²⁷)₂ where R²⁷independently is hydrogen, C₁₋₁₈ alkyl, C₂₋₁₈ alkenyl, or C₂₋₁₈ alkynyl,provided any such heteroatom is not adjacent to the N in the pyridinylring;

m is any integer from 0 to 2;

R³ is absent or is selected from hydrogen, aryl, aryloxy, arylthio,cycloalkyl, cycloalkenyl, cycloalkynyl, aryl-N(R¹⁰)—, or an aromaticheterocycle, where each said substituent is optionally substituted with1 or more R¹⁷, provided that for cycloalkenyl the double bond is notadjacent to a nitrogen;

R⁵ is selected from hydrogen; C₁₋₁₈ alkyl, C₂₋₁₈ alkenyl, C₂₋₁₈ alkynyl,C₁₋₁₈ alkoxy, C₁₋₁₈ alkylthio, halogen, —OH, —CN, —NO₂, —NR⁷R⁸,haloalkyloxy, haloalkyl, —C(═O)R⁹, —C(═O)OR⁹, —C(═S)R⁹, SH, aryl,aryloxy, arylthio, arylalkyl, C₁₋₁₈ hydroxyalkyl, C₃₋₁₀ cycloalkyl,C₃₋₁₀ cycloalkyloxy, C₃₋₁₀ cycloalkylthio, C₃₋₁₀ cycloalkenyl, C₇₋₁₀cycloalkynyl, or heterocycle;

R⁶ is selected from hydrogen, C₁₋₁₈ alkyl, C₂₋₁₈ alkenyl, C₂₋₁₈ alkynyl,C₁₋₁₈ alkoxy, C₁₋₁₈ alkylthio, C₁₋₁₈ alkylsulfoxide, C₁₋₁₈ alkylsulfone,C₁₋₁₈ halo-alkyl, C₂₋₁₈ halo-alkenyl, C₂₋₁₈ halo-alkynyl, C₁₋₁₈halo-alkoxy, C₁₋₁₈ halo-alkylthio, C₃₋₁₀ cycloalkyl, C₃₋₁₀ cycloalkenyl,C₇₋₁₀ cycloalkynyl, halogen, OH, CN, cyanoalkyl, —CO₂R¹⁸, NO₂, —NR⁷R⁸,C₁₋₁₈ haloalkyl, C(═O)R¹⁸, C(═S)R¹⁸, SH, aryl, aryloxy, arylthio,arylsulfoxide, arylsulfone, arylsulfonamide, aryl(C₁₋₁₈)alkyl,aryl(C₁₋₁₈)alkyloxy, aryl(C₁₋₁₈)alkylthio, heterocycle and C₁₋₁₈hydroxyalkyl, where each is optionally substituted with 1 to 3 R¹⁹;

R⁷ and R⁸ are independently selected from hydrogen, C₁₋₁₈ alkyl, C₁₋₁₈alkenyl, aryl, C₃₋₁₀ cycloalkyl, C₄₋₁₀ cycloalkenyl, heterocycle,—C(═O)R¹²; —C(═S)R¹², an amino acid residue linked through a carboxylgroup thereof, or R⁷ and R⁸ are taken together with the nitrogen to forma heterocycle;

R⁹ and R¹⁸ are independently selected from hydrogen, OH, C₁₋₁₈ alkyl,C₂₋₁₈ alkenyl, C₃₋₁₀ cycloalkyl, C₄₋₁₀ cycloalkenyl, C₁₋₁₈ alkoxy,—NR¹⁵R¹⁶, aryl, an amino acid residue linked through an amino group ofthe amino acid, CH₂OCH(═O)R^(9a), or CH₂OC(═O)OR^(9a) where R^(9a) isC₁-C₁₂ alkyl, C₆-C₂₀ aryl, C₆-C₂₀ alkylaryl or C₆-C₂₀ aralkyl;

R¹⁰ and R¹¹ are independently selected from the group consisting ofhydrogen, C₁₋₁₈ alkyl, C₂₋₁₈ alkenyl, C₃₋₁₀ cycloalkyl, C₄₋₁₀cycloalkenyl, aryl, —C(═O)R¹², heterocycle, or an amino acid residue;

R¹² is selected from the group consisting of hydrogen, C₁₋₁₈ alkyl,C₂₋₁₈ alkenyl, aryl, C₃₋₁₀ cycloalkyl, C₄₋₁₀ cycloalkenyl, or an aminoacid residue;

R¹⁵ and R¹⁶ are independently selected from hydrogen, C₁₋₁₈ alkyl, C₂₋₁₈alkenyl, C₂₋₁₈ alkynyl, aryl, C₃₋₁₀ cycloalkyl, C₄₋₁₀ cycloalkenyl, oran amino acid residue;

R¹⁷ is independently selected from the group consisting of hydrogen,C₁₋₁₈ alkyl, C₂₋₁₈ alkenyl, C₂₋₁₈ alkynyl, C₁₋₁₈ alkoxy, C₁₋₁₈alkylthio, C₁₋₁₈ alkylsulfoxide, C₁₋₁₈ alkylsulfone, C₁₋₁₈ halogenatedalkyl, C₂₋₁₈ halogenated alkenyl, C₂₋₁₈ halogenated alkynyl, C₁₋₁₈halogenated alkoxy, C₁₋₁₈ halogenated alkylthio, C₃₋₁₀ cycloalkyl, C₃₋₁₀cycloalkenyl, C₇₋₁₀ cycloalkynyl, halogen, OH, CN, CO₂H, CO₂R¹⁸, NO₂,NR⁷R⁸, haloalkyl, C(═O)R¹⁸, C(═S)R¹⁸, SH, aryl, aryloxy, arylthio,arylsulfoxide, arylsulfone, arylsulfonamide, arylalkyl, arylalkyloxy,arylalkylthio, heterocycle, C₁₋₁₈ hydroxyalkyl, where each of said aryl,aryloxy, arylthio, arylsulfoxide, arylsulfone, arylsulfonamide,arylalkyl, arylalkyloxy, arylalkylthio, heterocycle, or C₁₋₁₈hydroxyalkyl is optionally substituted with 1 or more R¹⁹;

R¹⁹ is selected from hydrogen, C₁₋₁₈ alkyl, C₂₋₁₈ alkenyl, C₂₋₁₈alkynyl, C₁₋₁₈ alkoxy, C₂₋₁₈ alkenyloxy, C₂₋₁₈ alkynyloxy, C₁₋₁₈alkylthio, C₃₋₁₀ cycloalkyl, C₄₋₁₀ cycloalkenyl, C₄₋₁₀ cycloalkynyl,halogen, —OH, —CN, cyanoalkyl, —NO₂, —NR²⁰R²¹, C₁₋₁₈ haloalkyl, C₁₋₁₈haloalkyloxy, —C(═O)R¹⁸, —C(═O)OR¹⁸, —OalkenylC(═O)OR¹⁸,—OalkylC(═O)NR²⁰R²¹, —OalkylOC(═O)R¹⁸, —C(═S)R¹⁸, SH, —C(═O)N(C₁₋₆alkyl), —N(H)S(O)(O)(C₁₋₆ alkyl), aryl, heterocycle, C₁₋₁₈alkylsulfone,arylsulfoxide, arylsulfonamide, aryl(C₁₋₁₈)alkyloxy, aryloxy, aryl(C₁₋₁₈alkyl)oxy, arylthio, aryl(C₁₋₁₈)alkylthio or aryl(C₁₋₁₈)alkyl, whereeach is optionally substituted with 1 to 3 of ═O, NR²⁰R²¹, CN, C₁₋₁₈alkoxy, heterocycle, C₁₋₁₈ haloalkyl, heterocycle alkyl, heterocycleconnected to R¹⁷ by alkyl, alkoxyalkoxy or halogen;

R²⁰ and R²¹ are independently selected from hydrogen, C₁₋₁₈ alkyl, C₂₋₁₈alkenyl, C₂₋₁₈ alkynyl, aryl, C₃₋₁₀ cycloalkyl, C₄₋₁₀ cycloalkenyl,—C(═O)R¹², or —C(═S)R¹²;

R²⁶ is independently selected from hydrogen, C₁₋₁₈ alkyl, C₃₋₁₀cycloalkyl, aryl, heterocycle, where each is optionally independentlysubstituted with 1 to 3 of C₁₋₆ alkyl, C₁₋₆ alkoxy, halo, CH₂OH,benzyloxy, and OH; and

salts, tautomers, stereoisomers and solvates thereof.

The invention further relates to the use of the formula (A) compounds inthe prophylaxis or treatment of viral infections. They inhibit HCV andare believed to be active against BVDV, HCV and Coxsackie virusinfections as well. The compounds of this invention are useful in themanufacture of a medicament for the treatment of these and otherretroviral or lentiviral infections. Therefore, these compoundsconstitute a new potent class of anti-viral compounds havingpharmaceutically desirable toxicity, bioavailability and otherpharmacological properties making them useful in the treatment andprevention of viral infections in animals, mammals and humans, morespecifically for the treatment and prevention of HCV virus infections.

The invention also relates to methods for preparation of such compoundsand pharmaceutical compositions comprising them.

DETAILED DESCRIPTION OF THE INVENTION

The physiologically acceptable salts of the compounds of the inventioninclude salts derived from an appropriate base, such as an alkali metal(for example, sodium), an alkaline earth (for example, magnesium),ammonium and NX⁴⁺ (wherein X is C₁-C₄ alkyl). Physiologically acceptablesalts of an hydrogen atom or an amino group include salts of organiccarboxylic acids such as acetic, benzoic, lactic, fumaric, tartaric,maleic, malonic, malic, isethionic, lactobionic and succinic acids;organic sulfonic acids, such as methanesulfonic, ethanesulfonic,benzenesulfonic and p-toluenesulfonic acids; and inorganic acids, suchas hydrochloric, sulfuric, phosphoric and sulfamic acids.Physiologically acceptable salts of a compound containing a hydroxygroup include the anion of said compound in combination with a suitablecation such as Na⁺ and NX⁴⁺ (wherein X typically is independentlyselected from H or a C₁-C₄ alkyl group). However, salts of acids orbases which are not physiologically acceptable may also find use, forexample, in the preparation or purification of a physiologicallyacceptable compound. All salts, whether or not derived form aphysiologically acceptable acid or base, are within the scope of thepresent invention.

The double bonds in formula (A) are depicted as facultative bonds. Thepyrrolopyridine core ring structures of the compounds of formula (A)have 3 or optionally 4 double bonds. All tautomeric positions possiblefor these bonds are intended to be represented by this depiction. Thestable positions of these bonds will depend upon their number and thepositions and identities of the other substituents on the nucleus, aswill be understood by those skilled in the art.

“Alkyl” is a normal, secondary, tertiary or cyclic hydrocarboncontaining 1 to 18 carbon atoms. The acyclic alkyl typically contains 1to 6 carbon atoms. Cycloalkyl usually contains 3 to 6 carbon atoms andconsists of 1 or 2 rings. Examples of “alkyl” include methyl, ethyl,1-propyl, 2-propyl, 1-butyl, 2-methyl-1-propyl(i-Bu), 2-butyl (s-Bu)2-methyl-2-propyl (t-Bu), 1-pentyl (n-pentyl), 2-pentyl, 3-pentyl,2-methyl-2-butyl, 3-methyl-2-butyl, 3-methyl-1-butyl, 2-methyl-1-butyl,1-hexyl, 2-hexyl, 3-hexyl, 2-methyl-2-pentyl, 3-methyl-2-pentyl,4-methyl-2-pentyl, 3-methyl-3-pentyl, 2-methyl-3-pentyl,2,3-dimethyl-2-butyl, 3,3-dimethyl-2-butyl, cyclopropyl, cyclobutyl,cyclopentyl and cyclohexyl, cyclopropyl, cyclobutyl, cyclopentyl,cycloheptyl, cyclooctyl and the like, or a C₇₋₁₀ polycyclic saturatedhydrocarbon radical having from 7 to 10 carbon atoms such as, forinstance, norbornyl, fentyl, trimethyltricycloheptyl or adamantyl.

“Alkenyl” is a normal, secondary, tertiary or cyclic hydrocarbon groupcontaining 1 to 3 double bonds and 3 to 18 carbon atoms. The acyclicportion typically contains 1 to 3 carbon atoms, and each cyclic portionusually contains 3 to 6 carbon atoms. Examples include, but are notlimited to, ethylene or vinyl (—CH═CH₂), allyl (—CH₂CH═CH₂),cyclopentenyl (—C₅H₇), 5-hexenyl (—CH₂CH₂CH₂CH₂CH═CH₂),1-cyclopent-1-enyl, 1-cyclopent-2-enyl, 1-cyclopent-3-enyl,1-cyclohex-1-enyl, 1-cyclohex-2-enyl, and 1-cyclohex-3-enyl. The doublebond optionally is in the cis or trans configuration.

“Alkynyl” is a normal, secondary, tertiary or cyclic hydrocarbon groupcontaining 1 to 3 triple bonds and 3 to 18 carbon atoms. Examplesinclude, but are not limited to, —C≡CH, —CH₂C≡CH, —CH₂C≡C-cyclohexyl, or—CH₂-cycloheptynyl.

The suffix “-ene” used in connection with alkyl, alkenyl and alkynylgroups refers to such groups with at least 2 sites of substitution. Suchpolyvalent hydrocarbon radicals include, but are not limited to,methylene (—CH₂—) 1,2-ethylene (—CH₂CH₂—), 1,3-propylene (—CH₂CH₂CH₂—),1,4-butylene (—CH₂CH₂CH₂CH₂—), 1,2-ethylene (—CH═CH—), —CC—, propargyl(—CH₂CC—), and 4-pentynyl (—CH₂CH₂CH₂CCH—).

“Aryl” means an aromatic hydrocarbon containing 1 or more rings,generally 1, 2 or 3, with 4 to 6 carbon atoms in each, ordinarily 5 or 6carbon atoms.

“Arylalkyl,” “arylalkenyl” and “arylalkynyl” means an alkyl, alkenyl oralkynyl radical, respectively, in which one of the hydrogen atoms,typically a terminal or sp3 carbon atom, is replaced with an arylradical. Typical arylalkyl groups include, but are not limited to,benzyl, 2-phenylethan-1-yl, 2-phenylethen-1-yl, naphthylmethyl,2-naphthylethan-1-yl, 2-naphthylethen-1-yl, naphthobenzyl,2-naphthophenylethan-1-yl and the like.

As noted, carbocycles optionally are found as single rings or multiplering systems. Ordinarily the hydrocarbons of the compounds of formula(A) are single rings. Monocyclic carbocycles generally have 3 to 6 ringatoms, still more typically 5 or 6 ring atoms. Bicyclic carbocyclestypically have 7 to 12 ring atoms, e.g. arranged as a bicyclo[4,5],[5,5], [5,6] or [6,6] system, or 9 or 10 ring atoms arranged as abicyclo[5,6] or [6,6] system.

If the number of carbon atoms is unspecified for a hydrocarbon,typically the number of carbon atoms will range from 1 to 18, exceptthat the number of carbons typically will range from 2 to 18 forunsaturated hydrocarbons and from 6 to 10 for aryl.

“Heterocyclic” or “heterocycle” means any 4, 5, 6, 7, 8 or 9 memberedsingle or fused ring system containing one or more heteroatoms selectedfrom the group consisting of O, N or S. Heterocycles optionally areentirely aromatic, entirely saturated, or contain 1 or more intra-ringsites of unsaturation, typically double bonds. Multiple heterocyclicrings (one or more of which contains a heteroatom) are bridged or spiro.Generally, the heterocyclic rings will be aromatic, and usually they aresingle rings. Heterocycles with 5 or 6 membered rings are typical.Usually, the heterocycles will contain 1 or 2 oxygen atoms with orwithout 1 or 2 N atoms. Also useful are heterocycles with 5 or 6 ringatoms and 1 to 3 N atoms. Monocycles are the typical choice. Examples ofheterocycles include oxazacyloalkyl, morpholinyl, dioxacycloalkyl,thiacycloalkenyl, pyridyl, dihydroypyridyl, tetrahydropyridyl(piperidyl), thiazolyl, tetrahydrothiophenyl, furanyl, thienyl,pyrrolyl, pyranyl, pyrazolyl, pyrazolidinyl, pyrazolinyl, imidazolyl,tetrazolyl, benzofuranyl, thianaphthalenyl, indolyl, indolenyl,quinolinyl, isoquinolinyl, benzimidazolyl, piperidinyl, piperazinyl,pyrrolidinyl, 2-pyrrolidonyl, pyrrolinyl, tetrahydrofuranyl,bis-tetrahydrofuranyl, tetrahydropyranyl, bis-tetrahydropyranyl,tetrahydroquinolinyl, tetrahydroisoquinolinyl, decahydroquinolinyl,octahydroisoquinolinyl, azocinyl, triazinyl, 6H-1,2,5-thiadiazinyl,2H,6H-1,5,2-dithiazinyl, thianthrenyl, pyranyl, isobenzofuranyl,chromenyl, xanthenyl, phenoxathinyl, 2H-pyrrolyl, isothiazolyl,isothiazoledinyl, isoxazolyl, oxazolinyl, pyrazinyl, pyridazinyl,pyrimidinyl, pyrrolidinyl, pyrrolinyl, indolizinyl, isoindolyl,3H-indolyl, 1H-indazoly, purinyl, 4H-quinolizinyl, isoquinolyl,quinolyl, phthalazinyl, naphthyridinyl, quinoxalinyl, quinazolinyl,cinnolinyl, pteridinyl, 4aH-carbazolyl, carbazolyl, β-carbolinyl,phenanthridinyl, acridinyl, pyrimidinyl, phenanthrolinyl, phenazinyl,phenothiazinyl, furazanyl, phenoxazinyl, isochromanyl, chromanyl,imidazolidinyl, imidazolinyl, pyrazolidinyl, pyrazolinyl, piperazinyl,indolinyl, isoindolinyl, quinuclidinyl, oxazolidinyl, benzotriazolyl,benzisoxazolyl, oxindolyl, benzoxazolinyl, benzothienyl, benzothiazolyland isatinoyl. Suitable heterocycles are exemplified in Rigaudy et al.,Nomenclature of Organic Chemistry, Sections A-H (1979) at pp. 53-76 andFletcher et al., Nomenclature of Organic Compounds, Adv. Chem. Ser. 126(1974) at pp 49-64.

The location on the heterocycle which provides the point ofattachment(s) to the rest of the compound of this invention is notcritical, but those skilled in the art will recognize substitution sitesthat are optimal for compound stability and/or ease of synthesis. Carbonbonded heterocycles typically are bonded at position 2, 3, 4, 5, or 6 ofa pyridine, position 3, 4, 5, or 6 of a pyridazine, position 2, 4, 5, or6 of a pyrimidine, position 2, 3, 5, or 6 of a pyrazine, position 2, 3,4, or 5 of a furan, tetrahydrofuran, thiofuran, thiophene, pyrrole ortetrahydropyrrole, position 2, 4, or 5 of an oxazole, imidazole orthiazole, position 3, 4, or 5 of an isoxazole, pyrazole, or isothiazole,position 2 or 3 of an aziridine, position 2, 3, or 4 of an azetidine,position 2, 3, 4, 5, 6, 7, or 8 of a quinoline or position 1, 3, 4, 5,6, 7, or 8 of an isoquinoline. Still more typically, carbon bondedheterocycles include 2-pyridyl, 3-pyridyl, 4-pyridyl, 5-pyridyl,6-pyridyl, 3-pyridazinyl, 4-pyridazinyl, 5-pyridazinyl, 6-pyridazinyl,2-pyrimidinyl, 4-pyrimidinyl, 5-pyrimidinyl, 6-pyrimidinyl, 2-pyrazinyl,3-pyrazinyl, 5-pyrazinyl, 6-pyrazinyl, 2-thiazolyl, 4-thiazolyl, or5-thiazolyl.

Nitrogen containing heterocycles are bonded at nitrogen or a carbon,typically a carbon atom. These include, for example, position 1 ofaziridine, 1-aziridyl, 1-azetedyl, 1-pyrrolyl, 1-imidazolyl,1-pyrazolyl, 1-piperidinyl, 2-pyrroline, 3-pyrroline, 2-imidazoline,3-imidazoline, 9-carbazole, 4-morpholine, 9-alpha or β-carboline,2-isoindole, 2-pyrazoline and 3-pyrazoline, and by analogy, azetidine,pyrrole, pyrrolidine piperidine, piperazine, indole, pyrazoline,indoline, imidazole, imidazolidine, 1H-indazole and isoindoline. Theseand other N-containing heterocycles are well-known to those skilled inthe art, and their linkage sites are a matter of discretion.

Sulfur containing heterocycles are bonded through carbon or sulfur. Theyinclude oxidized states such as —S(═O)(═O). In general, they are linkedin the compounds of formula (A) analogous to N-containing heterocycles.

“Alkoxy”, “cycloalkoxy”, “aryloxy”, “arylalkyloxy”, “oxy heterocycle”,“thioalkyl”, “thiocycloalkyl”, “arylthio”, and “arylalkylthio” meanssubstituents wherein an alkyl, cycloalkyl, aryl, or arylalkyl,respectively, are attached to an oxygen atom or a sulfur atom through asingle bond, such as but not limited to methoxy, ethoxy, propoxy,butoxy, thioethyl, thiomethyl, phenyloxy, benzyloxy, mercaptobenzyl andthe like.

“Halogen” means any atom selected from the group consisting of fluorine,chlorine, bromine and iodine, but typically is fluorine or chlorine.

Any substituent designation that is found in more than one site in acompound of this invention shall be independently selected.

When a group is stated to be substituted with “one or more” of anothergroup, this typically means 1 to 3 substituents, ordinarily 1, 2 or 3substitutents.

Those of skill in the art will also recognize that the compounds of theinvention may exist in many different protonation states, depending on,among other things, the pH of their environment. While the structuralformulae provided herein may depict the compounds in only one of severalpossible protonation states, it will be understood that these structuresare illustrative only, and that the invention is not limited to anyparticular protonation state—any and all protonated forms of thecompounds are intended to fall within the scope of the invention.

Amino Acids

An “Amino-acid” is a radical derived from a molecule having the chemicalformula H₂N—CHR²⁸—COOH, wherein R²⁸ is a side group of anaturally-occurring or known synthetic amino-acid. The amino acidsoptionally are substituted with hydrocarbon typically of 1 to 8 carbonsat one or more carboxyl or amino groups, whether those groups are on theside chain or are terminal groups after linking the amino acid to theremainder of the compound of this invention.

Optionally the amino acid residue is a hydrophobic residue such as mono-or di-alkyl or aryl amino acids, cycloalkylamino acids and the like.Optionally, the residue does not contain a sulfhydryl or guanidinosubstituent.

Naturally-occurring amino acid residues are those residues foundnaturally in plants, animals or microbes, especially proteins thereof.Polypeptides most typically will be substantially composed of suchnaturally-occurring amino acid residues. These amino acids are glycine,alanine, valine, leucine, isoleucine, serine, threonine, cysteine,methionine, glutamic acid, aspartic acid, lysine, hydroxylysine,arginine, histidine, phenylalanine, tyrosine, tryptophan, proline,asparagine, glutamine and hydroxyproline. Additionally, unnatural aminoacids, for example, valanine, phenylglycine and homoarginine are alsoincluded.

Generally, only one of any site in the parental molecule is substitutedwith an amino acid, although it is within the scope of this invention tointroduce amino acids at more than one permitted site. In general, theα-amino or α-carboxyl group of the amino acid are bonded to theremainder of the molecule, i.e., carboxyl or amino groups in the aminoacid side chains generally are not used to form the amide bonds with theparental compound (although these groups may need to be protected duringsynthesis of the conjugates).

The amino acid esters optionally are hydrolyzable in vivo or in vitrounder acidic (pH<3) or basic (pH>10) conditions. Optionally, they aresubstantially stable in the gastrointestinal tract of humans but arehydrolyzed enzymatically in blood or in intracellular environments.

R²⁸ usually is C₁-C₆ alkyl or C₁-C₆ alkyl substituted with amino,carboxyl, amide, carboxyl (as well as esters, as noted above), hydroxyl,C₆-C₇ aryl, guanidinyl, imidazolyl, indolyl, sulfhydryl, sulfoxide,and/or alkylphosphate. R²⁸ also is nitrogen to form a proline residuetaken together with the amino acid α-amino. However, R²⁸ is generallythe side group of the naturally-occurring amino acid disclosed above,for example H, —CH₃, —CH(CH₃)₂, —CH₂—CH(CH₃)₂, —CHCH₃—CH₂—CH₃,—CH₂—C₆H₅, —CH₂CH₂—S—CH₃, —CH₂OH, —CH(OH)—CH₃, —CH₂—SH, —CH₂—C₆H₄OH,—CH₂—CO—NH₂, —CH₂—CH₂—CO—NH₂, —CH₂—COOH, —CH₂—CH₂—COOH, —(CH₂)₄—NH₂ and—(CH2)₃—NH—C(NH₂)—NH₂. R²⁸ also includes 1-guanidinoprop-3-yl, benzyl,4-hydroxybenzyl, imidazol-4-yl, indol-3-yl, methoxyphenyl andethoxyphenyl.

Exemplary Embodiments

R¹ is generally aryl or aromatic heterocyle substituted with 1, 2 or 3R⁶ wherein R⁶ is generally halogen, C₁₋₁₈ alkoxy, or C₁₋₁₈ haloalkyl.The heterocycle for use in R¹ or any other substituent herein typicallywill have 5 or 6 ring atoms and 1, 2 and/or 3 N, O or S atoms, typically1, 2 or 3 N, 1 N and 1 O, or 1 or 2 N and 1 S atom in the ring. Usually,R¹ is phenyl substituted with 1 or 2 halogens, usually fluoro.

Y generally is a single bond, O, C₁₋₆ alkylene, C₂₋₆ alkenylene, C₂₋₆alkynylene or one of said groups containing 1 to 3, usually 1,heteroatoms selected from O, S or NR¹¹. Examples include —O(CH₂)₁₋₅—,—(CH₂)₁₋₄—O—(CH₂)₁₋₄—, —S—(CH₂)₁₋₅—, —(CH₂)₁₋₄—S—(CH₂)₁₋₄—,—NR¹¹—(CH₂)₁₋₅—, —(CH₂)₁₋₄—NR¹¹—(CH₂)₁₋₄ or C₃₋₁₀ cycloalkylidene.Typically, Y is —OCH₂—, —CH₂O—, C₁₋₂ alkylene, C₂₋₃ alkenylene, C₂₋₃alkynylene, O or a bond. Most typically, Y is a bond.

In general, YR¹ is not any one of H, an unsubstituted C₃₋₁₀ cycloalkylor C1-C6 alkyl. Typically YR¹ is halo or halomethyl-substituted(typically trihalomethyl)phenyl. These substituents are usually in orthoor meta positions, and usually there are 1 or 2 of them.

X usually is alkylene, alkynylene or alkenylene, typically alkylene.These hydrocarbons also optionally have an intrachain heteroatom,typically O or S. Examples include —CH₂—, —CH(CH₃)—, —CH₂—CH₂—,—CH₂—CH₂—CH₂—, —CH₂—CH₂—CH₂—CH₂, —(CH₂)₂₋₄—O—(CH₂)₂₋₄—,—(CH₂)₂₋₄—S—(CH₂)₂₋₄—, —(CH₂)₂₋₄—NR¹⁰—(CH₂)₂₋₄₋₉ C₃₋₁₀ cycloalkylidene,C₂₋₆ alkenylene (such as —CH═CH—CH₂—) and C₂₋₆ alkynylene. Usually, X is1 to 3 carbons, most usually methylene.

R³ generally is aryl or a heterocycle, typically an aromaticheterocycle. The heterocycle generally will contain 1, 2 or 3 N, S or Oatoms in the ring, usually is linked to X through a ring carbon atom andtypically contains 4 to 6, usually 5, total ring atoms. The R³ aryl orheterocycle ordinarily is substituted with 1, 2 or 3, usually 1, R¹⁷. R³optionally is not indolyl. R³ is typically a heterocyclic ring shown inTable 1, e.g. oxazolyl, etc. R³ generally is bonded to X via a ringcarbon atom. It usually is bonded to R¹⁷ through a ring carbon as well,but may be bonded through a ring nitrogen when the ring contains 3 Natoms. Usually, R¹⁷ is distal to X, i.e., these two groups arepositioned on substantially the opposite sides of R³.

When R³ is substituted with R¹⁷ then R¹⁷ typically is aryl or aheterocycle further substituted with 1, 2 or 3 R¹⁹.

R¹⁷ typically is selected from the group consisting of C₃₋₁₀ cycloalkyl,C₃₋₁₀ cycloalkenyl, C₇₋₁₀ cycloalkynyl, halogen, aryl, aryloxy,arylthio, arylsulfoxide, arylsulfone, arylsulfonamide, arylalkyl;arylalkyloxy (optionally a benzyloxy); arylalkylthio (optionally abenzylthio); a heterocycle; C₁₋₁₈ hydroxyalkyl, but typically is an arylor a heterocycle (usually aromatic), and where each of said aryl,aryloxy, arylthio, arylsulfoxide, arylsulfone, arylsulfonamide,arylalkyl, arylalkyloxy, arylalkylthio, or heterocycle is optionallysubstituted with 1 or more R¹⁹. Aryl here typically contains 5 or 6 ringatoms. R¹⁷ generally is positioned distally to X. Optionally, R¹⁷ is notC(O)R¹⁸.

R⁹ and R¹⁸ typically are H, OH or alkyl. R¹⁸ optionally is not NR¹⁵R¹⁶.

R⁵ typically is H.

R⁶ generally is halogen. Optionally, R⁶ is not C(O)R¹⁸.

R⁷, R⁸, R¹⁰, R¹¹, R¹³, R¹⁴, R¹⁵, R¹⁶, R²⁰, R²¹, R²³ and R²⁴ typicallyare independently H, halo, or C₁₋₁₈ alkyl.

R¹² and R²² typically are independently OH or alkyl.

R¹⁹ usually is H; C₁₋₁₈ alkyl; C₂₋₁₈ alkenyl; C₂₋₁₈ alkynyl; C₁₋₁₈alkoxy; alkenyloxy; alkynyloxy; C₁₋₁₈ alkylthio; C₃₋₁₀ cycloalkyl; C₄₋₁₀cycloalkenyl; C₄₋₁₀ cycloalkynyl; halogen; OH; CN; cyanoalkyl; NO₂;NR²⁰R²¹; haloalkyl; haloalkyloxy; C(═O)R¹⁸; C(═O)OR¹⁸;OalkenylC(═O)OR¹⁸; —OalkylC(═O)NR²⁰R²¹; aryl; heterocycle;—OalkylOC(═O)R¹⁸; C(═O)N(C₁₋₆ alkyl), N(H)S(O)(O)(C₁₋₆ alkyl);arylalkyloxy; aryloxy; arylalkyloxy; or arylalkyl; each of which isunsubstituted or substituted with 1 or more ═O; NR²⁰R²¹; CN; alkoxy;heterocycle; haloalkyl- or alkyl-substituted heterocycle; heterocyclelinked to R¹⁷ by alkyl; alkoxyalkoxy or halogen. R¹⁸ as a substituenthere is generally not H. R¹⁹ typically is independently halogen,N(R²⁰R²¹), alkoxy or halo-substituted alkyl or alkoxy. R¹⁹ usually ispositioned para and/or ortho to the carbon bound to R¹⁷.

R²⁶ is typically cyclopentyl, cyclohexyl or hydrogen.

Substituents optionally are depicted with or without bonds. Regardlessof bond indications, if a substituent is polyvalent (based on itsposition in the structure referred to), then any and all possibleorientations of the substituent are intended.

Haloalkyl or haloalkyloxy typically are —CF₃ or —OCF₃.

Formula (A) depicts optional single or double bonds. It will beunderstood that the bonds are present such that the aromatic nature ofthe nucleus of formula (A) is preserved, i.e., these formulae areintended to embrace all possible tautomers.

It will be understood that when applicants refer to a particularsubstituent site as “general”, “typical” or “usual” (or otherwisedesignate a subselection of group(s) for a given substituent site), thisis to be construed as expressly teaching individual compound(s) orcompound subgenera in which the selected site(s) possesses the recitedfeature(s) while the remaining substituent sites retain the full optionsset forth above for formula (A). The subselections are to be consideredto disclose expressly all compounds having the subselections incombination or subcombination, alone and/or taken together with the fullscope of remaining substituents described above for formula (A). Forinstance, disclosure of the substituent X and Y subselections above isdisclosure of (a) a subgenus in which X is methylene, Y is a bond andthe other groups are set forth in formula (A), (b) a subgenus in which Xis methylene and all the other groups (including Y) are set forth informula (A) and (c) a subgenus in which Y is a bond and all the othergroups (including X) are as set forth in formula (A). As anotherexample, the recitations above regarding R³ shall be construed asteaching at least compounds of formula (A) in which all groups otherthan R³ are as set forth above in formula (A) and R³ is aryl substitutedwith 1 R¹⁷, 2 R¹⁷ or 3 R¹⁷, any of these substituted with any of 1, 2 or3 R¹⁹ groups, and the same options for heterocycles or any of thespecified subclasses or specific heterocycles. This convention isadopted to provide support for subgenera without burdening thisapplication with redundant and/or unduly lengthy recitations ofbackground groups common to various subgenera.

The term “prodrug” as used herein refers to any compound that whenadministered to a biological system generates the drug substance, i.e.active ingredient, as a result of spontaneous chemical reaction(s),enzyme catalyzed chemical reaction(s), photolysis, and/or metabolicchemical reaction(s). A prodrug is thus a covalently modified analog orlatent form of a therapeutically-active compound.

Prodrugs

Certain of the compounds herein when substituted with appropriateselected functionalities are capable of acting as prodrugs. These arelabile functional groups which separate from an active inhibitorycompound during metabolism, systemically, inside a cell, by hydrolysis,enzymatic cleavage, or by some other process (Bundgaard, Hans, “Designand Application of Prodrugs” in Textbook of Drug Design and Development(1991), P. Krogsgaard-Larsen and H. Bundgaard, Eds. Harwood AcademicPublishers, pp. 113-191). These prodrug moieties can serve to enhancesolubility, absorption and lipophilicity to optimize drug delivery,bioavailability and efficacy. A “prodrug” is thus a covalently modifiedanalog of a therapeutically-active compound. A prodrug moiety of coursecan be therapeutically active in its own right.

Exemplary prodrug moieties include the hydrolytically sensitive orlabile esters (—CO₂R′) of carboxylic acids (—CO₂H) or other functionalgroups with an acidic proton which is bound to theimidazo[4,5-c]pyridine compounds of the invention. The R′ group of suchhydrolytically sensitive or labile esters may include: (i) acyloxymethylesters —CH₂C(═O)R^(9a); and (ii) acyloxymethyl carbonates—CH₂C(═O)OR^(9a) where R^(9a) is C₁-C₆ alkyl, C₁-C₆ substituted alkyl,C₆-C₂₀ aryl or C₆-C₂₀ substituted aryl. A close variant of theacyloxyalkyl ester, the alkoxycarbonyloxyalkyl ester (carbonate), mayalso enhance oral bioavailability as a prodrug moiety in the compoundsof the invention. An exemplary acyloxymethyl ester R group ispivaloyloxymethoxy, (POM) —CH₂C(═O)C(CH₃)₃. An exemplary acyloxymethylcarbonate prodrug moiety is pivaloyloxymethylcarbonate (POC)—CH₂C(═O)OC(CH₃)₃. Cleavable moieties capable of acting as prodrugfunctionalities are optionally linked at any tolerant site on thecompound of this invention, for example R³ and any of its substituents.

Utilities

The compounds of this invention, or the metabolites produced from thesecompounds in vivo, have a large number of uses. They are useful inimmunology, chromatography, diagnostics and therapeutics, among otherfields.

The compounds of formula (A) are conjugated to immunogenic polypeptidesas a reagent for eliciting antibodies capable of binding specifically tothe polypeptide, to the compounds or to their metabolic products whichretain immunologically recognized epitopes (sites of antibody binding).These immunogenic compositions therefore are useful as intermediates inthe preparation of antibodies for use in diagnostics, quality control,or the like, or in assays for the compounds of formula (A) or theirnovel metabolic products. The compounds are useful for raisingantibodies against otherwise non-immunogenic polypeptides, in that thecompounds serve as haptenic sites stimulating an immune response whichcross-reacts with the unmodified conjugated protein.

Conjugates of the compounds of formula (A) with immunogenic polypeptidessuch as albumin or keyhole limpet hemocyanin generally are useful asimmunogens. The polypeptides are conjugated at the same sites denotedfor amino acids. The metabolic products described above may retain asubstantial degree of immunological cross reactivity with the compoundsof the invention. Thus, the antibodies of this invention will be capableof binding to the unprotected compounds of the invention without bindingto the protected compounds. Alternatively the metabolic products will becapable of binding to the protected compounds and/or the metaboliticproducts without binding to the protected compounds of the invention, orwill be capable of binding specifically to any one or all three. Theantibodies desirably will not substantially cross-react withnaturally-occurring materials. Substantial cross-reactivity isreactivity under specific assay conditions for specific analytessufficient to interfere with the assay results.

The immunogens of this invention contain the compound of this inventionpresenting the desired epitope in association with an immunogenicsubstance. Within the context of the invention such association meanscovalent bonding to form an immunogenic conjugate (when applicable) or amixture of non-covalently bonded materials, or a combination of theabove. Immunogenic substances include adjuvants such as Freund'sadjuvant, immunogenic proteins such as viral, bacterial, yeast, plantand animal polypeptides, in particular keyhole limpet hemocyanin, serumalbumin, bovine thyroglobulin or soybean trypsin inhibitor, andimmunogenic polysaccharides. Typically, the compound having thestructure of the desired epitope is covalently conjugated to animmunogenic polypeptide or polysaccharide by the use of a polyfunctional(ordinarily bifunctional) cross-linking agent. Methods for themanufacture of hapten immunogens are conventional per se, and any of themethods used heretofore for conjugating haptens to immunogenicpolypeptides or the like are suitably employed here as well, taking intoaccount the functional groups on the precursors or hydrolytic productswhich are available for cross-linking and the likelihood of producingantibodies specific to the epitope in question as opposed to theimmunogenic substance.

Typically the polypeptide is conjugated to a site on the compound of theinvention distant from the epitope to be recognized.

The conjugates are prepared in conventional fashion. For example, thecross-linking agents N-hydroxysuccinimide, succinic anhydride oralkN═C═Nalk are useful in preparing the conjugates of this invention.The conjugates comprise a compound of the invention attached by a bondor a linking group of 1-100, typically, 1-25, more typically 1-10 carbonatoms to the immunogenic substance. The conjugates are separated fromstarting materials and by products using chromatography or the like, andthen are sterile filtered and vialed for storage.

Animals are typically immunized against the immunogenic conjugates orderivatives and antisera or monoclonal antibodies prepared inconventional fashion.

The compounds of this invention are useful as linkers, spacers oraffinity (typically hydrophobic) moieties in preparing affinityabsorption matrices. The compounds of the invention optionally are boundcovalently to an insoluble matrix and used for affinity chromatographyseparations, depending on the nature of the groups of the compounds, forexample compounds with pendant aryl groups are useful in makinghydrophobic affinity columns.

They also are useful as linkers and spacers in preparing immobilizedenzymes for process control, or in making immunoassay reagents. Thecompounds herein contain functional groups that are suitable as sitesfor cross-linking desired substances. For example, it is conventional tolink affinity reagents such as hormones, peptides, antibodies, drugs,and the like to insoluble substrates. These insolublized reagents areemployed in known fashion to absorb binding partners for the affinityreagents from manufactured preparations, diagnostic samples and otherimpure mixtures. Similarly, immobilized enzymes are used to performcatalytic conversions with facile recovery of enzyme. Bifunctionalcompounds are commonly used to link analytes to detectable groups inpreparing diagnostic reagents.

The compounds of this invention are labeled with detectable moietiessuch biotin, radioisotopes, enzymes and the like for diagnosticpurposes. Suitable techniques for accomplishing the labeling of thecompounds of formula (A) are well known and will be apparent to theartisan from consideration of this specification as a whole. Forexample, one suitable site for labeling is R17 or R19.

More typically, however, the compounds of the invention are employed forthe treatment or prophylaxis of viral infections such as yellow fevervirus, Dengue virus, hepatitis B virus, hepatitis G virus, ClassicalSwine Fever virus or the Border Disease Virus, but more particularlyflaviviral or picornaviral infections, in particular, HCV and BVDV.

The therapeutic compound(s) of this invention are administered to asubject mammal (including a human) by any means well known in the art,i.e. orally, intranasally, subcutaneously, intramuscularly,intradermally, intravenously, intra-arterially, parenterally or bycatheterization. The therapeutically effective amount of the compound(s)is a flaviviral or picornaviral growth inhibiting amount. Morepreferably, it is a flaviviral or picornaviral replication inhibitingamount or a flaviviral or picornaviral enzyme inhibiting amount of thecompounds of formula (A). This is believed to correspond to an amountwhich ensures a plasma level of between about 1 μg/ml and 100 mg/ml,optionally of 10 mg/ml. This optionally is achieved by administration ofa dosage of in the range of 0.001 mg to 60 mg, preferably 0.01 mg to 10mg, preferably 0.1 mg to 1 mg per day per kg bodyweight for humans.These are starting points for determining the optimal dosage of thecompound of this invention. The actual amount will depend upon manyfactors known to the artisan, including bioavailability of the compound,whether it contains a prodrug functionality, its metabolism anddistribution in the subject and its potency, among others. It typicallyis necessary to determine the proper dosing in the clinical setting, andthis is well within the skill of the ordinary artisan. Thetherapeutically effective amount of the compound(s) of this inventionoptionally are divided into several sub-units per day or areadministered at daily or more than one day intervals, depending upon thepathologic condition to be treated, the patient's condition and thenature of the compound of this invention.

As is conventional in the art, the evaluation of a synergistic effect ina drug combination may be made by analyzing the quantification of theinteractions between individual drugs, using the median effect principledescribed by Chou et al. in Adv. Enzyme Reg. (1984) 22:27 or tests suchas, but not limited to, the isobologram method, as previously describedby Elion et al. in J. Biol. Chem. (1954) 208:477-488 and by Baba et al.in Antimicrob. Agents Chemother. (1984) 25:515-517, using EC₅₀ forcalculating the fractional inhibitory concentration.

Suitable anti-viral agents for inclusion in combination antiviralcompositions or for coadministration in a course of therapy with thecompounds of this invention include, for instance, interferon alpha,ribavirin, a compound falling within the scope of disclosure ofEP1162196, WO 03/010141, WO 03/007945 and WO 03/010140, a compoundfalling within the scope of disclosure of WO 00/204425, and otherpatents or patent applications within their patent families, in amountsof 1 to 99.9% by weight compound of this invention, preferably from 1 to99% by weight, more preferably from 5 to 95% by weight as can be readilydetermined by one skilled in the art. Such co-administered agents neednot be formulated in the same dosage form as the compound of theinvention. They optionally are simply administered to the subject in thecourse of treatment along with a course of treatment with a compound offormula (A).

The present invention further provides veterinary compositionscomprising at least one active ingredient as above defined together witha veterinary carrier therefore, for example in the treatment of BVDV.Veterinary carriers are materials useful for the purpose ofadministering the composition and are excipients which are otherwiseinert or acceptable in the veterinary art and are compatible with thecompound of this invention. These veterinary compositions may beadministered orally, parenterally or by any other desired route.

Salts

The term “pharmaceutically acceptable salts” as used herein means thetherapeutically active non-toxic salt forms formed by the compounds offormula (A). Such salts may include those derived by combination ofappropriate cations such as alkali and alkaline earth metal ions orammonium and quaternary amino ions with an acid anion moiety, typicallya carboxylic acid.

The compounds of the invention may bear multiple positive or negativecharges. The net charge of the compounds of the invention may be eitherpositive or negative. Any associated counter ions are typically dictatedby the synthesis and/or isolation methods by which the compounds areobtained. Typical counter ions include, but are not limited to ammonium,sodium, potassium, lithium, halides, acetate, trifluoroacetate, etc.,and mixtures thereof. It will be understood that the identity of anyassociated counter ion is not a critical feature of the invention, andthat the invention encompasses the compounds in association with anytype of counter ion. Moreover, as the compounds can exist in a varietyof different forms, the invention is intended to encompass not onlyforms of the compounds that are in association with counter ions (e.g.,dry salts), but also forms that are not in association with counter ions(e.g., aqueous or organic solutions).

Metal salts typically are prepared by reacting the metal hydroxide witha compound of this invention. Examples of metal salts which are preparedin this way are salts containing Li+, Na+, Ca+2 and Mg+2 and K+. A lesssoluble metal salt can be precipitated from the solution of a moresoluble salt by addition of the suitable metal compound. In addition,salts may be formed from acid addition of certain organic and inorganicacids to basic centers, typically amines, or to acidic groups. Examplesof such appropriate acids include, for instance, inorganic acids such ashydrohalogen acids, e.g. hydrochloric or hydrobromic acid, sulfuricacid, nitric acid, phosphoric acid and the like; or organic acids suchas, for example, acetic, propanoic, hydroxyacetic, benzoic,2-hydroxypropanoic, 2-oxopropanoic, lactic, fumaric, tartaric, pyruvic,maleic, malonic, malic, salicylic (i.e. 2-hydroxybenzoic),p-aminosalicylic, isethionic, lactobionic, succinic oxalic and citricacids; organic sulfonic acids, such as methanesulfonic, ethanesulfonic,benzenesulfonic and p-toluenesulfonic acids; and inorganic acids, suchas hydrochloric, sulfuric, phosphoric and sulfamic acids, C1-C6alkylsulfonic, benzenesulfonic, p-toluenesulfonic, cyclohexanesulfamic,and the like. Preferred salts include mesylate and HCl.

The compounds of this invention include the solvates formed with thecompounds of formula (A) and their salts, such as for example hydrates,alcoholates and the like. The compositions herein comprise compounds ofthe invention in their un-ionized, as well as zwitterionic form, andcombinations with stoichiometric amounts of water as in hydrates.

Also included within the scope of this invention are the salts of thecompounds of formula (A) with one or more amino acids as describedabove. The amino acid typically is one bearing a side chain with a basicor acidic group, e.g., lysine, arginine or glutamic acid, or a neutralgroup such as glycine, serine, threonine, alanine, isoleucine, orleucine.

Salts of acids or bases which are not physiologically acceptable mayalso find use, for example, in the preparation or purification of acompound of formula (A). All salts, whether or not derived form aphysiologically acceptable acid or base, are within the scope of thepresent invention.

Isomers

The term “isomers” as used herein means all possible isomeric forms,including tautomeric and stereochemical forms, which the compounds offormula (A) may possess, but not including position isomers. Typically,the structures shown herein exemplify only one tautomeric or resonanceform of the compounds, but the corresponding alternative configurationsare contemplated as well. Unless otherwise stated, the chemicaldesignation of compounds denotes the mixture of all possiblestereochemically isomeric forms, said mixtures containing alldiastereomers and enantiomers (since the compounds of formula (A) mayhave one or more chiral centers), as well as the stereochemically pureor enriched isomers. More particularly, stereogenic centers may haveeither the R- or S-configuration, and double or triple bonds optionallyare in either the cis- or trans-configuration.

Enriched isomeric forms of a compound of this invention are defined as asingle isomer substantially free of the compound's other enantiomers ordiastereomers. In particular, the term “stereoisomerically enriched” or“chirally enriched” relates to compounds having a single stereoisomericproportion of at least about 80% (i.e. at least 90% of one isomer and atmost 10% of the other possible isomers), preferably at least 90%, morepreferably at least 94% and most preferably at least 97%. The terms“enantiomerically pure” and “diastereomerically pure” containundetectable levels of any other isomer.

Separation of stereoisomers is accomplished by standard methods known tothose in the art. One enantiomer of a compound of the invention can beseparated substantially free of its opposing enantiomer by a method suchas formation of diastereomers using optically active resolving agents(“Stereochemistry of Carbon Compounds,” (1962) by E. L. Eliel, McGrawHill; Lochmuller, C. H., (1975) J. Chromatogr., 113:(3) 283-302).Separation of isomers in a mixture can be accomplished by any suitablemethod, including: (1) formation of ionic, diastereomeric salts withchiral compounds and separation by fractional crystallization or othermethods, (2) formation of diastereomeric compounds with chiralderivatizing reagents, separation of the diastereomers, and conversionto the pure enantiomers, or (3) enantiomers can be separated directlyunder chiral conditions. Under method (1), diastereomeric salts can beformed by reaction of enantiomerically pure chiral bases such asbrucine, quinine, ephedrine, strychnine, a-methyl-b-phenylethylamine(amphetamine), and the like with asymmetric compounds bearing an acidicfunctionality, such as carboxylic acid and sulfonic acid.

The diastereomeric salts optionally are induced to separate byfractional crystallization or ionic chromatography. For separation ofthe optical isomers of amino compounds, addition of chiral carboxylic orsulfonic acids, such as camphorsulfonic acid, tartaric acid, mandelicacid, or lactic acid can result in formation of the diastereomericsalts. Alternatively, by method (2), the substrate to be resolved may bereacted with one enantiomer of a chiral compound to form adiastereomeric pair (Eliel, E. and Wilen, S. (1994). Stereochemistry ofOrganic Compounds, John Wiley & Sons, Inc., p. 322). Diastereomericcompounds can be formed by reacting asymmetric compounds withenantiomerically pure chiral derivatizing reagents, such as menthylderivatives, followed by separation of the diastereomers and hydrolysisto yield the free, enantiomerically enriched xanthene. A method ofdetermining optical purity involves making chiral esters, such as amenthyl ester or Mosher ester, a-methoxy-a-(trifluoromethyl)phenylacetate (Jacob III. (1982) J. Org. Chem. 47:4165), of the racemicmixture, and analyzing the NMR spectrum for the presence of the twoatropisomeric diastereomers. Stable diastereomers can be separated andisolated by normal- and reverse-phase chromatography following methodsfor separation of atropisomeric naphthyl-isoquinolines (Hoye, T., WO96/15111). Under method (3), a racemic mixture of two asymmetricenantiomers is separated by chromatography using a chiral stationaryphase. Suitable chiral stationary phases are, for example,polysaccharides, in particular cellulose or amylose derivatives.Commercially available polysaccharide based chiral stationary phases areChiralCeI™ CA, OA, OB5, OC5, OD, OF, OG, OJ and OK, and Chiralpak™ AD,AS, OP(+) and OT(+). Appropriate eluents or mobile phases for use incombination with said polysaccharide chiral stationary phases are hexaneand the like, modified with an alcohol such as ethanol, isopropanol andthe like. (“Chiral Liquid Chromatography” (1989) W. J. Lough, Ed.Chapman and Hall, New York; Okamoto, (1990). “Optical resolution ofdihydropyridine enantiomers by High-performance liquid chromatographyusing phenylcarbamates of polysaccharides as a chiral stationary phase”,J. of Chromatogr. 513:375-378).

Metabolites

The present invention also provides the in vivo metabolic products ofthe compounds described herein, to the extent such products are noveland unobvious over the prior art. Such products may result for examplefrom the oxidation, reduction, hydrolysis, amidation, esterification andthe like of the administered compound, primarily due to enzymaticprocesses. Accordingly, the invention includes novel and unobviouscompounds produced by a process comprising contacting a compound of thisinvention with a mammal for a period of time sufficient to yield ametabolic product thereof. Such products typically are identified bypreparing a radiolabelled (e.g. C14 or H3) compound of the invention,administering it parenterally in a detectable dose (e.g. greater thanabout 0.5 mg/kg) to an animal such as rat, mouse, guinea pig, monkey, orto man, allowing sufficient time for metabolism to occur (typicallyabout 30 seconds to 30 hours) and isolating its conversion products fromthe urine, blood or other biological samples. These products are easilyisolated since they are labeled (others are isolated by the use ofantibodies capable of binding epitopes surviving in the metabolite). Themetabolite structures are determined in conventional fashion, e.g. by MSor NMR analysis. In general, analysis of metabolites is done in the sameway as conventional drug metabolism studies well-known to those skilledin the art. The conversion products, so long as they are not otherwisefound in vivo, are useful in diagnostic assays for therapeutic dosing ofthe compounds of the invention even if they possess no antiviralactivity of their own.

Formulations

The compounds of the invention optionally are formulated withconventional pharmaceutical carriers and excipients, which will beselected in accord with ordinary practice. Tablets will containexcipients, glidants, fillers, binders and the like. Aqueousformulations are prepared in sterile form, and when intended fordelivery by other than oral administration generally will be isotonic.Formulations optionally contain excipients such as those set forth inthe “Handbook of Pharmaceutical Excipients” (1986) and include ascorbicacid and other antioxidants, chelating agents such as EDTA,carbohydrates such as dextrin, hydroxyalkylcellulose,hydroxyalkylmethylcellulose, stearic acid and the like.

Subsequently, the term “pharmaceutically acceptable carrier” as usedherein means any material or substance with which the active ingredientis formulated in order to facilitate its application or dissemination tothe locus to be treated, for instance by dissolving, dispersing ordiffusing the said composition, and/or to facilitate its storage,transport or handling without impairing its effectiveness. Thepharmaceutically acceptable carrier may be a solid or a liquid or a gaswhich has been compressed to form a liquid, i.e. the compositions ofthis invention can suitably be used as concentrates, emulsions,solutions, granulates, dusts, sprays, aerosols, suspensions, ointments,creams, tablets, pellets or powders.

Suitable pharmaceutical carriers for use in the said pharmaceuticalcompositions and their formulation are well known to those skilled inthe art, and there is no particular restriction to their selectionwithin the present invention. They may also include additives such aswetting agents, dispersing agents, stickers, adhesives, emulsifyingagents, solvents, coatings, antibacterial and antifungal agents (forexample phenol, sorbic acid, chlorobutanol), isotonic agents (such assugars or sodium chloride) and the like, provided the same areconsistent with pharmaceutical practice, i.e. carriers and additiveswhich do not create permanent damage to mammals. The pharmaceuticalcompositions of the present invention may be prepared in any knownmanner, for instance by homogeneously mixing, coating and/or grindingthe active ingredients, in a one-step or multi-steps procedure, with theselected carrier material and, where appropriate, the other additivessuch as surface-active agents. may also be prepared by micronisation,for instance in view to obtain them in the form of microspheres usuallyhaving a diameter of about 1 to 10 gm, namely for the manufacture ofmicrocapsules for controlled or sustained release of the activeingredients.

Suitable surface-active agents, also known as emulgent or emulsifier, tobe used in the pharmaceutical compositions of the present invention arenon-ionic, cationic and/or anionic materials having good emulsifying,dispersing and/or wetting properties. Suitable anionic surfactantsinclude both water-soluble soaps and water-soluble syntheticsurface-active agents. Suitable soaps are alkaline or alkaline-earthmetal salts, unsubstituted or substituted ammonium salts of higher fattyacids (C₁₀-C₂₂), e.g. the sodium or potassium salts of oleic or stearicacid, or of natural fatty acid mixtures obtainable form coconut oil ortallow oil. Synthetic surfactants include sodium or calcium salts ofpolyacrylic acids; fatty sulphonates and sulphates; sulphonatedbenzimidazole derivatives and alkylarylsulphonates. Fatty sulphonates orsulphates are usually in the form of alkaline or alkaline-earth metalsalts, unsubstituted ammonium salts or ammonium salts substituted withan alkyl or acyl radical having from 8 to 22 carbon atoms, e.g. thesodium or calcium salt of lignosulphonic acid or dodecylsulphonic acidor a mixture of fatty alcohol sulphates obtained from natural fattyacids, alkaline or alkaline-earth metal salts of sulphuric or sulphonicacid esters (such as sodium lauryl sulphate) and sulphonic acids offatty alcohol/ethylene oxide adducts. Suitable sulphonated benzimidazolederivatives preferably contain 8 to 22 carbon atoms. Examples ofalkylarylsulphonates are the sodium, calcium or alcoholamine salts ofdodecylbenzene sulphonic acid or dibutyl-naphthalenesulphonic acid or anaphthalene-sulphonic acid/formaldehyde condensation product. Alsosuitable are the corresponding phosphates, e.g. salts of phosphoric acidester and an adduct of p-nonylphenol with ethylene and/or propyleneoxide, or phospholipids. Suitable phospholipids for this purpose are thenatural (originating from animal or plant cells) or syntheticphospholipids of the cephalin or lecithin type such as e.g.phosphatidylethanolamine, phosphatidylserine, phosphatidylglycerine,lysolecithin, cardiolipin, dioctanylphosphatidyl-choline,dipalmitoylphoshatidyl-choline and their mixtures.

Suitable non-ionic surfactants include polyethoxylated andpolypropoxylated derivatives of alkylphenols, fatty alcohols, fattyacids, aliphatic amines or amides containing at least 12 carbon atoms inthe molecule, alkylarenesulphonates and dialkylsulphosuccinates, such aspolyglycol ether derivatives of aliphatic and cycloaliphatic alcohols,saturated and unsaturated fatty acids and alkylphenols, said derivativespreferably containing 3 to 10 glycol ether groups and 8 to 20 carbonatoms in the (aliphatic) hydrocarbon moiety and 6 to 18 carbon atoms inthe alkyl moiety of the alkylphenol. Further suitable non-ionicsurfactants are water-soluble adducts of polyethylene oxide withpoylypropylene glycol, ethylenediaminopolypropylene glycol containing 1to 10 carbon atoms in the alkyl chain, which adducts contain 20 to 250ethyleneglycol ether groups and/or 10 to 100 propyleneglycol ethergroups. Such compounds usually contain from I to 5 ethyleneglycol unitsper propyleneglycol unit. Representative examples of non-ionicsurfactants are nonylphenol-polyethoxyethanol, castor oil polyglycolicethers, polypropylene/polyethylene oxide adducts,tributylphenoxypolyethoxyethanol, polyethyleneglycol andoctylphenoxypolyethoxyethanol. Fatty acid esters of polyethylenesorbitan (such as polyoxyethylene sorbitan trioleate), glycerol,sorbitan, sucrose and pentaerythritol are also suitable non-ionicsurfactants.

Suitable cationic surfactants include quaternary ammonium salts,particularly halides, having 4 hydriocarbon radicals optionallysubstituted with halo, phenyl, substituted phenyl or hydroxy; forinstance quaternary ammonium salts containing as N-substituent at leastone C8C22 alkyl radical (e.g. cetyl, lauryl, palmityl, myristyl, oleyland the like) and, as further substituents, unsubstituted or halogenatedlower alkyl, benzyl and/or hydroxy-lower alkyl radicals.

A more detailed description of surface-active agents suitable for thispurpose may be found for instance in “McCutcheon's Detergents andEmulsifiers Annual” (MC Publishing Crop., Ridgewood, N.J., 1981),“Tensid-Taschenbucw’, 2 d ed. (Hanser Verlag, Vienna, 1981) and“Encyclopaedia of Surfactants, (Chemical Publishing Co., New York,1981).

Compounds of the invention and their physiologically acceptable salts(hereafter collectively referred to as the active ingredients) may beadministered by any route appropriate to the condition to be treated,suitable routes including oral, rectal, nasal, topical (includingocular, buccal and sublingual), vaginal and parenteral (includingsubcutaneous, intramuscular, intravenous, intradermal, intrathecal andepidural). The preferred route of administration may vary with forexample the condition of the recipient.

While it is possible for the active ingredients to be administered aloneit is preferable to present them as pharmaceutical formulations. Theformulations, both for veterinary and for human use, of the presentinvention comprise at least one active ingredient, as above described,together with one or more pharmaceutically acceptable carriers thereforeand optionally other. therapeutic ingredients. The carrier(s) optimallyare “acceptable” in the sense of being compatible with the otheringredients of the formulation and not deleterious to the recipientthereof. The formulations include those suitable for oral, rectal,nasal, topical (including buccal and sublingual), vaginal or parenteral(including subcutaneous, intramuscular, intravenous, intradermal,intrathecal and epidural) administration. The formulations mayconveniently be presented in unit dosage form and may be prepared by anyof the methods well known in the art of pharmacy. Such methods includethe step of bringing into association the active ingredient with thecarrier which constitutes one or more accessory ingredients. In generalthe formulations are prepared by uniformly and intimately bringing intoassociation the active ingredient with liquid carriers or finely dividedsolid carriers or both, and then, if necessary, shaping the product.

Formulations of the present invention suitable for oral administrationmay be presented as discrete units such as capsules, cachets or tabletseach containing a predetermined amount of the active ingredient; as apowder or granules; as solution or a suspension in an aqueous liquid ora non-aqueous liquid; or as an oil-in-water liquid emulsion or awater-in-oil liquid emulsion. The active ingredient may also bepresented as a bolus, electuary or paste.

A tablet may be made by compression or molding, optionally with one ormore accessory ingredients. Compressed tablets may be prepared bycompressing in a suitable machine the active ingredient in afree-flowing form such as a powder or granules, optionally mixed with abinder, lubricant, inert diluent, preservative, surface active ordispersing agent. Molded tablets may be made by molding in a suitablemachine a mixture of the powdered compound moistened with an inertliquid diluent. The tablets may optionally be coated or scored and maybe formulated so as to provide slow or controlled release of the activeingredient therein. For infections of the eye or other external tissuese.g. mouth and skin, the formulations are optionally applied as atopical ointment or cream containing the active ingredient(s) in anamount of, for example, 0.075 to 20% w/w (including active ingredient(s)in a range between 0.1% and 20% in increments of 0.1% w/w such as 0.6%w/w, 0.7% w/w, etc), preferably 0.2 to 15% w/w and most preferably 0.5to 10% w/w. When formulated in an ointment, the active ingredients maybe employed with either a paraffinic or a water-miscible ointment base.Alternatively, the active ingredients may be formulated in a cream withan oil-in-water cream base. If desired, the aqueous phase of the creambase may include, for example, at least 30% w/w of a polyhydric alcohol,i.e. an alcohol having two or more hydroxyl groups such as propyleneglycol, butane 1,3-diol, mannitol, sorbitol, glycerol and polyethyleneglycol (including PEG400) and mixtures thereof. The topical formulationsmay desirably include a compound which enhances absorption orpenetration of the active ingredient through the skin or other affectedareas. Examples of such dermal penetration enhancers includedimethylsulfoxide and related analogs.

The oily phase of the emulsions of this invention may be constitutedfrom known ingredients in a known manner. While the phase may comprisemerely an emulsifier (otherwise known as an emulgent), it desirablycomprises a mixture of at least one emulsifier with a fat or an oil orwith both a fat and an oil. Optionally, a hydrophilic emulsifier isincluded together with a lipophilic emulsifier which acts as astabilizer. It is also preferred to include both an oil and a fat.Together, the emulsifier(s) with or without stabilizer(s) make up theso-called emulsifying wax, and the wax together with the oil and fatmake up the so-called emulsifying ointment base which forms the oilydispersed phase of the cream formulations.

The choice of suitable oils or fats for the formulation is based onachieving the desired cosmetic properties, since the solubility of theactive compound in most oils likely to be used in pharmaceuticalemulsion formulations is very low. Thus the cream should optionally be anon-greasy, non-staining and washable product with suitable consistencyto avoid leakage from tubes or other containers. Straight or branchedchain, mono- or dibasic alkyl esters such as di-isoadipate, isocetylstearate, propylene glycol diester of coconut fatty acids, isopropylmyristate, decyl oleate, isopropyl palmitate, butyl stearate,2-ethylhexyl palmitate or a blend of branched chain esters known asCrodamol CAP may be used, the last three being preferred esters. Thesemay be used alone or in combination depending on the propertiesrequired. Alternatively, high melting point lipids such as white softparaffin and/or liquid paraffin or other mineral oils can be used.

Formulations suitable for topical administration to the eye also includeeye drops wherein the active ingredient is dissolved or suspended in asuitable carrier, especially an aqueous solvent for the activeingredient. The active ingredient is optionally present in suchformulations in a concentration of 0.5 to 20%, advantageously 0.5 to 10%particularly about 1.5% w/w. Formulations suitable for topicaladministration in the mouth include lozenges comprising the activeingredient in a flavored basis, usually sucrose and acacia ortragacanth; pastilles comprising the active ingredient in an inert basissuch as gelatin and glycerin, or sucrose and acacia; and mouthwashescomprising the active ingredient in a suitable liquid carrier.

Formulations for rectal administration may be presented as a suppositorywith a suitable base comprising for example cocoa butter or asalicylate. Formulations suitable for nasal administration wherein thecarrier is a solid include a coarse powder having a particle size forexample in the range 20 to 500 microns (including particle sizes in arange between 20 and 500 microns in increments of 5 microns such as 30microns, 35 microns, etc), which is administered in the manner in whichsnuff is taken, i.e. by rapid inhalation through the nasal passage froma container of the powder held close up to the nose. Suitableformulations wherein the carrier is a liquid, for administration as forexample a nasal spray or as nasal drops, include aqueous or oilysolutions of the active ingredient. Formulations suitable for aerosoladministration may be prepared according to conventional methods and maybe delivered with other therapeutic agents.

Formulations suitable for vaginal administration may be presented aspessaries, tampons, creams, gels, pastes, foams or spray formulationscontaining in addition to the active ingredient such carriers as areknown in the art to be appropriate.

Formulations suitable for parenteral administration include aqueous andnon-aqueous sterile injection solutions which may contain anti-oxidants,buffers, bacteriostats and solutes which render the formulation isotonicwith the blood of the intended recipient; and aqueous and non-aqueoussterile suspensions which may include suspending agents and thickeningagents. The formulations may be presented in unit-dose or multi-dosecontainers, for example sealed ampoules and vials, and may be stored ina freeze-dried (lyophilized) condition requiring only the addition ofthe sterile liquid carrier, for example water for injections,immediately prior to use. Extemporaneous injection solutions andsuspensions may be prepared from sterile powders, granules and tabletsof the kind previously described.

Preferred unit dosage formulations are those containing a daily dose orunit daily sub-dose, as herein above recited, or an appropriate fractionthereof, of an active ingredient.

It should be understood that in addition to the ingredients particularlymentioned above the formulations of this invention may include otheragents conventional in the art having regard to the type of formulationin question, for example those suitable for oral administration mayinclude flavoring agents.

Compounds of the invention can be used to provide controlled releasepharmaceutical formulations containing copolymers, methylcellulose,carboxymethylcellulose, protamine sulfate and the like. The rate of drugrelease and duration of action may also be controlled by incorporatingthe active ingredient into particles, e.g. microcapsules, of a polymericsubstance such as hydrogels, polylactic acid, hydroxymethylcellulose,polymethyl methacrylate and the other above-described polymers. Suchmethods include colloid drug delivery systems like liposomes,microspheres, microemulsions, nanoparticles, nanocapsules and so on.Depending on the route of administration, the pharmaceutical compositionmay require protective coatings. Pharmaceutical forms suitable forinjectionable use include sterile aqueous solutions or dispersions andsterile powders for the extemporaneous preparation thereof. Typicalcarriers for this purpose therefore include biocompatible aqueousbuffers, ethanol, glycerol, propylene glycol, polyethylene glycol andthe like and mixtures thereof.

In view of as active ingredient one or more compounds of the invention(“controlled release formulations”) in which the release of the activeingredient can be controlled and regulated to allow less frequencydosing or to improve the pharmacokinetic or toxicity profile of a giveninvention compound. Controlled release formulations adapted for oraladministration in which discrete units comprising one or more compoundsof the invention can be prepared according to conventional methods.

Additional ingredients may be included in order to control the durationof action of the active ingredient in the composition. Control releasecompositions may thus be achieved by selecting appropriate polymercarriers such as for example polyesters, polyamino acids, polyvinylpyrrolidone, ethylene-vinyl acetate the fact that, when several activeingredients are used in combination, they do not necessarily bring outtheir joint therapeutic effect directly at the same time in the mammalto be treated, the corresponding composition may also be in the form ofa medical kit or package containing the two ingredients in separate butadjacent repositories or compartments. In the latter context, eachactive ingredient may therefore be formulated in a way suitable for anadministration route different from that of the other ingredient, e.g.one of them may be in the form of an oral or parenteral formulationwhereas the other is in the form of an ampoule for intravenous injectionor an aerosol.

Examples

The following examples illustrate the present invention without beinglimited thereto. Part A represents the preparation of the compoundswhereas Part B represents the pharmacological examples and Part Crepresents biological activities of selected compounds of the invention.

Part A Preparation of2-(2-Fluoro-phenyl)-6-(4-trifluoromethoxy-benzyl)-6H-pyrrolo[2,3-c]pyridine

To a solution of 2-(2-Fluoro-phenyl)-1H-pyrrolo[2,3-c]pyridine (50 mg,0.244 mmole) in DMF (1 ml) was added 10% (w/v) aqueous NaOH (113 μl,0.28 mmole) followed by a solution of 4-trifluoromethoxybenzyl chloride(60 mg, 0.28 mmole) in DMF (0.5 ml). The reaction mixture was stirred atroom temperature for 1 hour. The crude reaction mixture was purified byreverse phase HPLC with mass directed collection. Obtained 9.2 mg (8%)of 2-(2-Fluorophenyl)-6-(4-trifluoromethoxy-benzyl)-6H-pyrrolo[2,3-c]pyridiniumtrifluoroacetate after repurification.

Preparation of2-(2-Fluoro-phenyl)-5-(4-trifluoromethoxy-benzyl)-5H-pyrrolo[3,2-c]pyridine

To a solution of 2-(2-Fluoro-phenyl)-1H-pyrrolo[3,2-c]pyridine (50 mg,0.244 mmole) in DMF (1 ml) was added 10% (w/v) aqueous NaOH (113 μl,0.28 mmole) followed by a solution of 4-trifluoromethoxybenzyl chloride(60 mg, 0.28 mmole) in DMF (0.5 ml). The reaction mixture was stirred atroom temperature for 1 hour. The crude reaction mixture was purified byreverse phase HPLC with mass directed collection. Obtained 87 mg (74%)of2-(2-Fluoro-phenyl)-5-(4-trifluoromethoxy-benzyl)-5H-pyrrolo[3,2-c]pyridiniumtrifluoroacetate.

Preparation of2-(2-Fluoro-phenyl)-6-[3-(4-fluoro-2-trifluoromethyl-phenyl)-isoxazol-5-ylmethyl]-6H-pyrrolo[2,3-c]pyridinetrifluoroacetate

To a solution of 2-(2-Fluoro-phenyl)-1H-pyrrolo[2,3-c]pyridine (50 mg,0.244 mmole) in DMF (1 ml) was added 10% (w/v) aqueous NaOH (113 μl,0.28 mmole) followed by a solution of5-Chloromethyl-3-(4-fluoro-2-trifluoromethyl-phenyl)-isoxazole (79 mg,0.28 mmole) in DMF (0.5 ml). The reaction mixture was stirred at roomtemperature for 12 hours. The crude reaction mixture was purified byreverse phase HPLC with mass directed collection. Obtained 109 mg (81%)of2-(2-Fluoro-phenyl)-6-[3-(4-fluoro-2-trifluoromethyl-phenyl)-isoxazol-5-ylmethyl]-6H-pyrrolo[2,3-c]pyridiniumtrifluoroacetate.

Preparation of2-(2-Fluoro-phenyl)-5-[3-(4-fluoro-2-trifluoromethyl-phenyl)-isoxazol-5-ylmethyl]-5H-pyrrolo[3,2-c]pyridinetrifluoroacetate

To a solution of 2-(2-Fluoro-phenyl)-1H-pyrrolo[3,2-c]pyridine (50 mg,0.244 mmole) in DMF (1 ml) was added 10% (w/v) aqueous NaOH (113 μl,0.28 mmole) followed by a solution of5-Chloromethyl-3-(4-fluoro-2-trifluoromethyl-phenyl)-isoxazole (79 mg,0.28 mmole) in DMF (0.5 ml). The reaction mixture was stirred at roomtemperature for 12 hours. The crude reaction mixture was purified byreverse phase HPLC with mass directed collection. Obtained 115 mg (86%)of2-(2-Fluoro-phenyl)-5-[3-(4-fluoro-2-trifluoromethyl-phenyl)-isoxazol-5-ylmethyl]-5H-pyrrolo[3,2-c]pyridiniumtrifluoroacetate.

Preparation of3-cyclohexyl-6-((3-(4-fluoro-2-(trifluoromethyl)phenyl)isoxazol-5-yl)methyl)-2-phenyl-6H-pyrrolo[2,3-c]pyridine

To triethylsilylcyclohexylacetylene (1.36 g, 6.20 mmol) synthesized asdescribed in Tet. Lett. 41: 907 (2000) and 4-iodo-pyridin-3-ylamine(1.62 g, 2.27 mmol) in anhydrous DMF (62 mL) was added Pd(dppf)Cl₂.CH₂Cl₂ (253 mg, 0.31 mmol) followed by anhydrous LiCl (263 mg, 6.20mmol) and Na₂CO₃ (1.31 g, 12.40 mmol). The reaction mixture was heatedto 100° C. for 24 h after which the reaction was diluted with H₂O andEtOAc and filtered over celite. The organics were separated, washed withsaturated aqueous NaHCO₃, and dried over sodium sulfate. After removalof solvent, the crude product was purified by column chromatography onsilica (3:2 ethyl acetate/hexanes) to provide 590 mgs (30%) of desiredproduct.

Bis(pyridine)iodonium tetrafluoroboroate (250 mg, 0.67 mmol) wasdissolved in anhydrous CH₂Cl₂ (4 mL). To this solution was added asolution of 2-(triethylsilyl)pyrrolopyridine (192 mg, 0.61 mmol) inCH₂Cl₂ (2.7 mL) followed by trific acid (183 mg, 1.22 mmol). Afterstirring for 1.5 h at room temperature, the reaction was diluted withH₂O and the organics were separated. The organic layer was washed with a10% solution of aqueous Na₂S₂O₃, dried over sodium sulfate, and removedvia rotary evaporation. The crude material (100 mg, 50%) was usedwithout further purification: LCMS found 327.2 (M⁺+H, C₁₃H₁₅IN₂ requires327.2).

To 2-bromo-5-nitrotoluene (500 mg, 2.31 mmol) and 4-chlorophenylboronicacid (626 mg, 4.00 mmol) in DMF (15 mL) was added a solution of Na₂CO₃(695 mg, 6.56 mmol) in H₂O (8 mL) followed by the addition of Pd(PPh₃)₄(125 mg, 5 mol %). The reaction was heated in a microwave reactor at200° C. for 3 min. The reaction mixture was filtered over celite andsolvents removed under reduced pressure. The crude product was purifiedby column chromatography on silica (2:1 hexanes/ethyl acetate) toprovide 483 mg (84%) of desired product.

2-(4-Chlorophenyl)-5-nitrotoluene (483 mg, 1.95 mmol) and NBS (382 mg,2.15 mmol) were combined in CCl₄ (13 mL). After heating to 88° C., AIBN(32 mg, 0.2 mmol) was added and reacted for 20 h. The reaction wascooled to room temperature and diluted with CH₂Cl₂ and H₂O. The organicswere separated, washed with saturated aqueous NaHCO₃, and dried oversodium sulfate. After removal of solvent, the crude material was useddirectly in the next reaction.

To α-bromo-2-(4-chlorophenyl)5-nitrotoluene (297 mg, 0.91 mmol)4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenol (167 mg, 0.76mmol) in DMF (3 mL) was added K₂CO₃ (209 mg, 1.51 mmol). After stirringfor 2 h at room temperature, the reaction was diluted with H₂O andextracted with EtOAc. The organics were separated, washed with saturatedaqueous NaHCO₃, and dried over sodium sulfate. After removal of solvent,the crude product was purified by column chromatography on silica (9:1hexanes/ethyl acetate) to provide 160 mg (45%) of desired product: ¹HNMR (CDCl₃, 300 MHz) δ 8.54 (d, 1H), 8.25 (dd, 1H), 7.74 (d, 2H),7.27-7.49 (m, 5H), 6.86 (d, 2H), 4.98 (s, 2H), 1.34 (s, 12H).

To 3-cyclohexyl-2-iodo-1H-pyrrolo[2,3-c]pyridine (34 mg, 0.1 mmol) andsubstituted boronic ester (58 mg, 0.13 mmol) in DMF (0.69 mL) was addeda solution of Na₂CO₃ (33 mg, 0.31 mmol) in H₂O (0.35 mL) followed byPd(PPh₃)₄ (6 mg, 5 mol %). The reaction mixture was heated to 90° C. for12 h after which the reaction was filtered over a C-18 SPE columnflushing with MeOH. After removal of solvent, the crude product waspurified by column chromatography on silica (3% MeOH in CH₂Cl₂) toprovide 6.1 mg (11%) of the title compound: ¹H NMR (CD₃OD, 300 MHz) δ8.79 (s, 1H), 8.54 (d, 1H), 8.31 (dd, 1H), 8.11 (q, 2H), 7.49-7.63 (m,7H), 7.12 (d, 2H), 5.16 (s, 2H), 3.00 (m, 1H), 1.78-2.02 (m, 7H), 1.42(m, 3H); LCMS found 538.4 (M⁺+H, C₃₂H₂₈ClN₃O₃ requires 539.0).

To 3-cyclohexyl-2-iodo-1H-pyrrolo[2,3-c]pyridine (70 mg, 0.22 mmol) andphenylboronic acid (31 mg, 0.26 mmol) in toluene/EtOH (1:1, 1.76 mL) wasadded a solution of Na₂CO₃ (68 mg, 0.65 mmol) in H₂O (0.44 mL) followedby Pd(dppf) Cl₂.CH₂Cl₂ (8.8 mg, 5 mol %). The reaction mixture washeated to 90° C. for 12 h after which the reaction was filtered over aC-18 SPE column flushing with MeOH. After removal of solvent, the crudeproduct was purified by column chromatography on silica (4% MeOH inCH₂Cl₂) to provide 30 mg (83%) of desired product: ¹H NMR CD₃OD, 300MHz) δ 8.70 (s, 1H), 8.06 (d, 1H), 7.92 (dd, 1H), 7.50-7.60 (m, 5H),2.98 (m, 1H), 1.78-2.06 (m, 7H), 1.30-1.47 (m, 3H); LCMS found 277.5(M⁺+H, C₁₉H₂₀N₂ requires 277.4).

To 3-cyclohexyl-2-phenyl-1H-pyrrolo[2,3-c]pyridine (9 mg, 33 μmol) and5-(chloromethyl)-3-(4-fluoro-2-(trifluoromethyl)phenyl)isoxazole (11 mg,39 μmol) in DMF (326 μL) was added 10% aqueous NaOH (16 mL, 39 μmol).After stirring 12 h at room temperature, the reaction was neutralizedwith triethylamine and the crude purified by reverse phase HPLC toprovide 4.5 mg (27%) of the title compound: ¹H NMR (CD₃OD, 300 MHz) δ9.2 (s, 1H), 8.36 (s, 2H), 7.55-7.72 (m, 8H), 6.82 (s, 1H), 6.12 (s,2H), 3.04 (m, 1H), 1.78-2.06 (m, 7H), 1.30-1.50 (m, 3H); LCMS found520.3 (M⁺+H, C₃₀H₂₆F₄N₃O requires 520.5).

Part B

Methodology for Determination of Antiviral and Cytostatic Activity

Anti-HCV Assay/Replicon Assay

Huh-5-2 cells [a cell line with a persistent HCV repliconI389luc-ubi-neo/NS3-3′/5.1; replicon with fireflyluciferase-ubiquitin-neomycin phosphotransferase fusion protein andEMCV-IRES driven NS3-5B HCV polyprotein] was cultured in RPMI medium(Gibco) supplemented with 10% fetal calf serum, 2 mM L-glutamine (LifeTechnologies), 1× non-essential amino acids (Life Technologies); 100IU/ml penicillin and 100 ug/ml streptomycin and 250 ug/ml G418(Geneticin, Life Technologies). Cells were seeded at a density of 7000cells per well in 96 well View Plate™ (Packard) in medium containing thesame components as described above, except for G418. Cells were allowedto adhere and proliferate for 24 hr. At that time, culture medium wasremoved and serial dilutions of the test compounds were added in culturemedium lacking G418. Interferon alfa 2a (500 IU) was included as apositive control. Plates were further incubated at 37° C. and 5% CO₂ for72 hours. Replication of the HCV replicon in Huh-5 cells results inluciferase activity in the cells. Luciferase activity is measured byadding 50 μl of 1× Glo-lysis buffer (Promega) for 15 minutes followed by50 μl of the Steady-Glo Luciferase assay reagent (Promega). Luciferaseactivity is measured with a luminometer and the signal in eachindividual well is expressed as a percentage of the untreated cultures.Parallel cultures of Huh-5-2 cells, seeded at a density of 7000cells/well of classical 96-well cel culture plates (Becton-Dickinson)are treated in a similar fashion except that no Glo-lysis buffer orSteady-Glo Luciferase reagent is added. Instead the density of theculture is measured by means of the MTS method (Promega).

Quantitative Analysis of HCV RNA by Taqman Real-Time RT-PCR

Replicon cells were plated at 7.5×10³ cells per well in a 96-well plateplates at 37° C. and 5% CO₂ in Dulbecco's modified essential mediumcontaining 10% fetal calf serum, 1% nonessential amino acids and 1 mg/mlGeneticin. After allowing 24 h for cell attachment, different dilutionsof compound were added to the cultures. Plates were incubated for 5days, at which time RNA was extracted using the Qiamp Rneazyi Kit(Qiagen, Hilden, Germany). A 50 μL PCR reaction contained TaqMan EZbuffer (50 mmol/L Bicine, 115 mmol/L potassium acetate, 0.01 mmol/LEDTA, 60 nmol/L 6-carboxy-X-rhodamine, and 8% glycerol, pH 8.2; PerkinElmer Corp./Applied Biosystems), 300 μmol/L deoxyadenosine triphosphate,300 μmol/L deoxyguanosine triphosphate, 300 μmol/L deoxycytidinetriphosphate, 600 μmol/L deoxyuridine triphosphate, 200 μmol/L forwardprimer [5′-ccg gcT Acc Tgc ccA TTc], 200 μmol/L reverse primer [ccA GaTcAT ccT gAT cgA cAA G], 100 μmol/L TaqMan probe [6-FAM-AcA Tcg cAT cgAgcg Agc Acg TAc-TAMRA], 3 mmol/L manganese acetate, 0.5 U AmpEraseuracil-N-glycosylase, 7.5 U rTth DNA polymerase, and 10 μl of RNAelution. After initial activation of uracil-N-glycosylase at 50° C. for2 minutes, RT was performed at 60° C. for 30 minutes, followed byinactivation of uracil-N-glycosylase at 95° C. for 5 minutes. SubsequentPCR amplification consisted of 40 cycles of denaturation at 94° C. for20 seconds and annealing and extension at 62° C. for 1 minute in an ABI7700 sequence detector. For each PCR run, negative template and positivetemplate samples were used. The cycle threshold value (Ct-value) isdefined as the number of PCR cycles for which the signal exceeds thebaseline, which defines a positive value. The sample was considered tobe positive if the Ct-value was <50. Results are expressed as genomicequivalents (GE).

Part C

Biological Activities of Selected Compounds

Representative compounds of the invention are shown in Table 1. Thecompounds shown were active, with HCV replicon EC₅₀ values less than 100uM.

TABLE 1 Compound Structure 1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

We claim:
 1. A compound having the general formula (A),

wherein: the dotted lines represent at least 3, optionally 4 doublebonds, provided that no two double bonds are adjacent to one another;each A is independently CR²⁶; R¹ is selected from hydrogen, aryl,heterocycle, C₁-C₁₀ alkoxy, C₁-C₁₀ thioalkyl, C₁-C₁₀ alkyl-amino, C₁-C₁₀dialkyl-amino, C₃₋₁₀ cycloalkyl, C₄₋₁₀ cycloalkenyl, and C₄₋₁₀cycloalkynyl, wherein each are optionally substituted with 1 or more R⁶;Y is a single bond provided that YR¹ is not hydrogen R² and R⁴ areindependently selected from hydrogen, C₁₋₁₈ alkyl, C₂₋₁₈ alkenyl, C₂₋₁₈alkynyl, C₁₋₁₈ alkoxy, C₁₋₁₈ alkylthio, halogen, —OH, —CN, —NO₂, —NR⁷R⁸,haloalkyloxy, haloalkyl, —C(═O)R⁹, —C(═S)R⁹, SH, aryl, aryloxy,arylthio, arylalkyl, C₁₋₁₈ hydroxyalkyl, C₃₋₁₀ cycloalkyl, C₃₋₁₀cycloalkyloxy, C₃₋₁₀ cycloalkylthio, C₃₋₁₀ cycloalkenyl, C₃₋₁₀cycloalkynyl, and heterocycle; X is absent or is selected from hydrogen,C₁-C₁₀ alkylene, C₂₋₁₀ alkenylene and C₂₋₁₀ alkynylene, wherein 1 to3-C(H)═, —C(E) or —CH₂— groups of each alkylene, alkenylene oralkynylene optionally are independently replaced with a heteroatom orheteroatom group selected from —O—, ═O, —OR²⁷, —S—, ═S, —SR²⁷, —NR²⁷,and —N(R²⁷)₂ where R²⁷ independently is hydrogen, C₁₋₁₈ alkyl, C₂₋₁₈alkenyl, or C₂₋₁₈ alkynyl; m is any integer from 0 to 2; R³ is anaromatic heterocycle optionally substituted with 1 or more R¹⁷, providedthat for cycloalkenyl the double bond is not adjacent to a nitrogen; R⁵is selected from hydrogen; C₁₋₁₈ alkyl, C₂₋₁₈ alkenyl, C₂₋₁₈ alkynyl,C₁₋₁₈ alkoxy, C₁₋₁₈ alkylthio, halogen, —OH, —CN, —NO₂, —NR⁷R⁸,haloalkyloxy, haloalkyl, —C(═O)R⁹, —C(═O)OR⁹, —C(═S)R⁹, SH, aryl,aryloxy, arylthio, arylalkyl, C₁₋₁₈ hydroxyalkyl, C₃₋₁₀ cycloalkyl,C₃₋₁₀ cycloalkyloxy, C₃₋₁₀ cycloalkylthio, C₃₋₁₀ cycloalkenyl, C₇₋₁₀cycloalkynyl, and heterocycle; R⁶ is selected from hydrogen, C₁₋₁₈alkyl, C₂₋₁₈ alkenyl, C₂₋₁₈ alkynyl, C₁₋₁₈ alkoxy, C₁₋₁₈ alkylthio,C₁₋₁₈ alkylsulfoxide, C₁₋₁₈ alkylsulfone, C₁₋₁₈ halo-alkyl, C₂₋₁₈halo-alkenyl, C₂₋₁₈ halo-alkynyl, C₁₋₁₈ halo-alkoxy, C₁₋₁₈halo-alkylthio, C₃₋₁₀ cycloalkyl, C₃₋₁₀ cycloalkenyl, C₇₋₁₀cycloalkynyl, halogen, OH, CN, cyanoalkyl, —CO₂R¹⁸, NO₂, —NR⁷R⁸, C₁₋₁₈haloalkyl, C(═O)R¹⁸, C(═S)R¹⁸, SH, aryl, aryloxy, arylthio,arylsulfoxide, arylsulfone, arylsulfonamide, aryl(C₁₋₁₈)alkyl,aryl(C₁₋₁₈)alkyloxy, aryl(C₁₋₁₈)alkylthio, heterocycle and C₁₋₁₈hydroxyalkyl, where each is optionally substituted with 1 to 3 R¹⁹; R⁷and R⁸ are independently selected from hydrogen, C₁₋₁₈ alkyl, C₁₋₁₈alkenyl, aryl, C₃₋₁₀ cycloalkyl, C₄₋₁₀ cycloalkenyl, heterocycle,—C(═O)R¹²; —C(═S)R¹², and an amino acid residue linked through acarboxyl group thereof, or R⁷ and R⁸ are taken together with thenitrogen to form a heterocycle; R⁹ and R¹⁸ are independently selectedfrom hydrogen, OH, C₁₋₁₈ alkyl, C₂₋₁₈ alkenyl, C₃₋₁₀ cycloalkyl, C₄₋₁₀cycloalkenyl, C₁₋₁₈ alkoxy, —NR¹⁵R¹⁶, aryl, an amino acid residue linkedthrough an amino group of the amino acid, CH₂OCH(═O)R^(9a), andCH₂OC(═O)OR^(9a) where R^(9a) is C₁-C₁₂ alkyl, C₆-C₂₀ aryl, C₆-C₂₀alkylaryl or C₆-C₂₀ aralkyl; R¹⁰ and R¹¹ are independently selected fromthe group consisting of hydrogen, C₁₋₁₈ alkyl, C₂₋₁₈ alkenyl, C₃₋₁₀cycloalkyl, C₄₋₁₀ cycloalkenyl, aryl, —C(═O)R¹², heterocycle, and anamino acid residue; R¹² is selected from the group consisting ofhydrogen, C₁₋₁₈ alkyl, C₂₋₁₈ alkenyl, aryl, C₃₋₁₀ cycloalkyl, C₄₋₁₀cycloalkenyl, and an amino acid residue; R¹⁵ and R¹⁶ are independentlyselected from hydrogen, C₁₋₁₈ alkyl, C₂₋₁₈ alkenyl, C₂₋₁₈ alkynyl, aryl,C₃₋₁₀ cycloalkyl, C₄₋₁₀ cycloalkenyl, and an amino acid residue; R¹⁷ isindependently selected from the group consisting of hydrogen, C₁₋₁₈alkyl, C₂₋₁₈ alkenyl, C₂₋₁₈ alkynyl, C₁₋₁₈ alkoxy, C₁₋₁₈ alkylthio,C₁₋₁₈ alkylsulfoxide, C₁₋₁₈ alkylsulfone, C₁₋₁₈ halogenated alkyl, C₂₋₁₈halogenated alkenyl, C₂₋₁₈ halogenated alkynyl, C₁₋₁₈ halogenatedalkoxy, C₁₋₁₈ halogenated alkylthio, C₃₋₁₀ cycloalkyl, C₃₋₁₀cycloalkenyl, C₇₋₁₀ cycloalkynyl, halogen, OH, CN, CO₂H, CO₂R¹⁸, NO₂,NR⁷R⁸, haloalkyl, C(═O)R¹⁸, C(═S)R¹⁸, SH, aryl, aryloxy, arylthio,arylsulfoxide, arylsulfone, arylsulfonamide, arylalkyl, arylalkyloxy,arylalkylthio, heterocycle, and C₁₋₁₈ hydroxyalkyl, where each of saidaryl, aryloxy, arylthio, arylsulfoxide, arylsulfone, arylsulfonamide,arylalkyl, arylalkyloxy, arylalkylthio, heterocycle, or C₁₋₁₈hydroxyalkyl is optionally substituted with 1 or more R¹⁹; R¹⁹ isselected from hydrogen, C₁₋₁₈ alkyl, C₂₋₁₈ alkenyl, C₂₋₁₈ alkynyl, C₁₋₁₈alkoxy, C₂₋₁₈ alkenyloxy, C₂₋₁₈ alkynyloxy, C₁₋₁₈ alkylthio, C₃₋₁₀cycloalkyl, C₄₋₁₀ cycloalkenyl, C₄₋₁₀ cycloalkynyl, halogen, —OH, —CN,cyanoalkyl, —NO₂, —NR²OR²¹, C₁₋₁₈ haloalkyl, C₁₋₁₈ haloalkyloxy,—C(═O)R¹⁸, —C(═O)OR¹⁸, —OalkenylC(═O)OR¹⁸, —OalkylC(═O)NR²OR²¹,—OalkylOC(═O)R¹⁸, —C(═S)R¹⁸, SH, —C(═O)N(C₁₋₆ alkyl), —N(H)S(O)(O)(C₁₋₆alkyl), aryl, heterocycle, C₁₋₁₈alkylsulfone, arylsulfoxide,arylsulfonamide, aryl(C₁₋₁₈)alkyloxy, aryloxy, aryl(C₁₋₁₈ alkyl)oxy,arylthio, aryl(C₁₋₁₈)alkylthio and aryl(C₁₋₁₈)alkyl, where each isoptionally substituted with 1 to 3 of ═O, NR²⁰R²¹, CN, C₁₋₁₈ alkoxy,heterocycle, C₁₋₁₈ haloalkyl, heterocycle alkyl, heterocycle connectedto R¹⁷ by alkyl, alkoxyalkoxy or halogen; R²⁰ and R²¹ are independentlyselected from hydrogen, C₁₋₁₈ alkyl, C₂₋₁₈ alkenyl, C₂₋₁₈ alkynyl, aryl,C₃₋₁₀ cycloalkyl, C₄₋₁₀ cycloalkenyl, —C(═O)R¹², and —C(═S)R¹²; R²⁶ isindependently selected from hydrogen, C₁₋₁₈ alkyl, C₃₋₁₀ cycloalkyl,aryl, and heterocycle, where each is optionally independentlysubstituted with 1 to 3 of C₁₋₆ alkyl, C₁₋₆ alkoxy, halo, CH₂OH,benzyloxy, or OH; or a salt, tautomer, stereoisomer, or solvate thereof.2. The compound according to claim 1, wherein R²⁶ is hydrogen.
 3. Thecompound of claim 1, wherein R¹ is phenyl substituted with 1 to 3 R⁶. 4.The compound according to claim 1, wherein X is C1-C3 alkyl and R³ isindependently substituted with 1 or 2 R¹⁷.
 5. The compound of claim 4wherein R¹⁷ independently is substituted with 1 or 2 R¹⁹.
 6. Thecompound of claim 5 wherein R¹ is aryl independently substituted with 1or 2 R⁶.
 7. The compound of claim 5 wherein R², R⁴ and R⁵ are hydrogen.8. The compound of claim 5 wherein X is methylene.
 9. The compound ofclaim 5 wherein R³ is a five membered heteroaryl containing 1 to 3 N, Oand/or S ring atoms.
 10. The compound of claim 5 wherein R³ isisoxazolyl or pyridizinyl.
 11. The compound of claim 5 wherein R¹⁹independently is aryl.
 12. The compound of claim 11 wherein aryl isphenyl.
 13. The compound of claim 5 wherein R¹⁹ is independentlysubstituted with 1 or 2 R⁶.
 14. The compound of claim 13 wherein R⁶ isindependently halo or C1-C6 haloalkyl.
 15. The compound of claim 13wherein R¹⁹ is substituted with 2 R⁶.
 16. The compound of claim 1wherein X is methyl and R³ is isoxazole substituted with 1 R¹⁷.
 17. Thecompound of claim 16 wherein R¹⁷ is substituted with 1 R¹⁹.
 18. Thecompound of claim 17 wherein R¹⁹ is substituted with 1 or 2 R⁶.
 19. Thecompound of claim 1 wherein R²⁶ is C3-C6 cycloalkyl.
 20. A compositioncomprising a compound of claim 1 and a pharmaceutically acceptableexcipient or carrier.